1. Field of the Invention
The present invention relates to a paging procedure, and more particularly, to a paging method and apparatus in a carrier aggregation (CA) environment of a mobile communication system.
2. Description of the Related Art
A conventional mobile communication system, for example, a 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) system may support a high rate of mobile communication service using a maximum of 20 MHz. However, as a service type, a required data rate, and the like are being diversified, a faster mobile communication system has been desired. For this, an International Mobile Telecommunication (IMT)-Advanced system has supported a relatively wide band, for example, a maximum of 100 MHz compared to conventional 3GPP LTE Release-8. In general, even though a frequency of a mobile communication uses a contiguous spectrum, a support for non-contiguous spectrum has been currently required due to a complexity of a user element and the like. In addition, a reuse of a frequency being used in an existing mobile communication has been required. A band expansion of at least 20 MHz may be performed through a carrier aggregation (CA). A relatively wide frequency bandwidth may be secured through integration of component carriers (CCs). From a view of an LTE user element, each CC may appear as an LTE frequency. Accordingly, it is possible to maintain a compatibility with a previous system.
Since a conventional mobile communication system does not consider a method with respect to the above non-contiguous spectrum, it is difficult to provide an effective communication method using CCs of the non-contiguous spectrum newly required. In the case of paging for an incoming call setup to a user equipment, a CC that is selected by the user equipment and thereby is in an idle state may be different from a CC for the user equipment that is determined by an evolved Node-B (eNB). In this case, it may be difficult to smoothly perform scheduling of the eNB, or an additional procedure such as a handover to another CC may need to be performed after the call setup. When the eNB may not control a CC of the user equipment, load balancing for effectively using resources between CCs may not be properly performed. Accordingly, a congestion may occur in a particular CC. The additional procedure after the call setup may deteriorate a quality of service (QoS) due to an increase in the ineffective call processing procedure.